In large scale computing systems, it is often necessary to provide an operator with detailed information regarding the presence and status of mass storage devices. In order to provide such functionality, many storage solutions utilize a storage backplane that interfaces with a host bus adapter (“HBA”) and that directly mates with one or more mass storage devices. A storage backplane may include an integrated enclosure management device, which provides facilities for generating visual indicators regarding the status of connected mass storage devices. For instance, in some solutions, individual light-emitting diodes (“LEDs”) may be driven by an enclosure management device on a storage backplane for displaying information regarding the activity, failure, rebuild status, and other information for each of the mass storage devices connected to the storage backplane.
Storage backplanes that are compatible with Serial Attached SCSI (“SAS”) or Serial Advanced Technology Attachment (“SATA”) mass storage devices utilize SAS internal connectors. The SAS internal connectors consist of a receptacle connector, which is utilized on each slot of the storage backplane, and a compatible drive-side plug connector, which is utilized on compatible mass storage devices. The drive-side plug connector is utilized on all SAS and SATA mass storage devices.
The SAS internal connectors define a pin (the READY LED pin) for conveying drive ready status. This pin is defined as a vendor-specific pin and, therefore, manufacturers are not required to implement the pin. Most mass storage manufacturers, however, utilize this pin to indicate drive activity for SATA devices. But, this pin cannot be utilized to directly drive an LED. In order to utilize this pin to drive an LED, a physically large and complex open collector or open drain transmitter circuit must be utilized. These types of circuits can occupy significant valuable board space on a storage backplane.
The SAS internal connectors also do not define a pin dedicated to conveying information regarding the detected presence or absence of a mass storage device. As a result, it can be difficult for a storage backplane to determine when a mass storage device has been connected, or “mated.” It can be similarly difficult for a mass storage device to determine when a mass storage device has been disconnected, or “unmated.”
It is with respect to these considerations and others that the disclosure presented herein is made.